Semiconductor devices, such as a die or chip, are typically coupled with a substrate made from organic-type or ceramic-type material. The substrate may provide power and ground to the semiconductor devices as well as communication paths for I/O data signals. As semiconductor devices operate at continually higher data rates and higher frequencies, high-speed communications are necessary between a die and substrate, or between two dies. Conventional interfaces between a semiconductor device and a substrate and conventional interfaces between two semiconductor devices, typically utilize bonding wires, vias, solder bumps, and/or controlled-collapsed-chip-connections (e.g., C4). One problem with these conventional interfaces is that they are typically capacitive or inductive resulting in the inability to effectively communicate high-speed and/or high-frequency signals. For example, bond wires and vias can be inductive. Another problem with these conventional interfaces is that they typically have a narrow bandwidth inhibiting communication of broadband or wideband signals. Because high-speed digital signals may have a broad frequency spectrum, the use of conventional interfaces may be unsuitable for present and future die substrate and die-die data signal communications.
Another problem with conventional die-substrate interfaces is the coefficient of thermal expansion (CTE) mismatch between a die and a substrate. This mismatch may result in excessive mechanical stresses on the semiconductor device and may result in reliability problems. Yet another problem with conventional die-substrate and die-die interfaces is that conventional signaling typically uses the low-frequency portion of the electromagnetic spectrum resulting in high power consumption.
Thus there is a general need for an improved interface for high-speed signaling.